High-tension cut-out and the like



Oct. 22, 1929. A. '5. PEARL HIGH TENSION CUT- GUT AND THE LIKE Filed March 21, 192? 3 Sheets-Sheet l a Q -17 O00 z I luv 94 JVAV I E 32 3 a 5 Oct. 22', 1929. A. s. PEARL HIGH TENSION CUT-OUT AND THE LIKE Filed March 21, 1.927 :5 Sheats-Shees Oct. 22, 1929. A. s. PEARL HIGH TENSION CUT-OUT AND THE LIKE 3 Sheets-Sheet 3 Filed March 21, 1927 Patented bet. 2 2, 1929 PATENT OFFICE ALLEN S. PEARL, OF CHICAGO, ILLINOIS HIGH-TENSION cur-our AND THE LIKE A plication filed March 21, 1927. Serial No. 176,915.

The present invention has to do with improvements in cutouts for high tension circuits. The invention has reference especially to devices for opening the high tension cir- 5 cuits automatically in case of overload.

The features of inventionherein disclosed are especially intended for use in connection with very high voltage circuits such as those operating at 10,000 volts and upwards; but it will presently appear that the features of the invention are not limited to this or any other voltage of operation.

The cutout herein disclosed depends for its principle of operation upon the fact that certain gases are good conductors of electricity whereas other gases, or the same gases under difierent conditions are practically perfect insulators against the flow of high volt age current. For example, certain gases are conductors of electricitywhen said gases are present under a given condition of gas pressure, whereas they become practically perfect insulators against the flow of high voltage current at other pressures. An instance of this condition is found in the case of so called neon gas. This gas has good conductivity for high voltage currents when said gas is present at approximately 610 mms. of mercury, absolute pressure but the same neon gas becomes practically a perfect insulator against the flow of high voltage current when the pressure has increased to atmospheric pressure, that is, approximately 30 cms. mercury, absolute pressure. In another case, the neon gas of 6-10 mms, mercury absolute pressure is a good conductor; but when displaced by air, or when mixed with air at substantially atmospheric pressure it becomes a good insulator against flow of high voltage current.

According to the present invention I avail myself of the foregoing general principles, and I have devised structures operating upon these principles and capable of automatically bringing these principles. into operation upon the existence of an overload or excessive current to be opened. For example, in one case I have provided a tubular conductor for the high voltage current, said conductor being 5 sealed in gas tight fashion and containing the conductor gas. In conjunction with said tubular structure I have also provided means for automatically destroying the physical conditions of the conducting gas upon the existence of an overload, so that the conducting qualities of said gas is thus destroyed and the circuit is thereby automatically opened.

In connection with the foregoing I have also provided in one form of device an arrangement whereby the pressure of said conducting gas may be immediately modified upon the existence of an overload condition to such an extent as will destroy the conducting quality of said gas and thereby open the oilcuit. In this arrangement there is provided a tube or chamber containing the rarefied gas under the pressure conditions at which it is a good conductor; and there is also provided in association with said tube or chamber another receptacle also containing gas, either the same or different from that in the first mentioned chamber, the two chambers being normally sealed from eachother in gas tight fashion. Upon the existence of an overload condition the seal is automatically broken so that the two chambers are instantly placed in communication with each other, therebymodifying the pressure conditions in the conducting chamber to the extent necessary to destroy the conductivity of the gas therein.

In another case I have provided a chamber containing the conducting gas under the conditions at which it is a good conductor, said chamber being normally sealed; and in conjunction therewith I have provided means for expelling said gas from said chamber upon the existence of an overload condition. This expelling of the conducting gas may be accomplished either by an explosive displacement or by a physical bodily displacement due to the action of a piston or other similar moving part.

In thus mentioning certain possible embodiments of the features of my invention I do not intend to limit myself thereto except .95 as I may do so in the claims but I mention these applications of the features of the invention merely by way of illustration.

' Keeping the foregoing in mind, Fig. 1 on the drawings shows a vertical elevation, partly in section showing one" embodiment of a' device embodying the features of the present invention;

Fig. 2 shows a cross section on the line 2-2 of Fi 1 looking in the direction of the arrows fiut on enlarged scale;

Fig. 3 shows a vertical section through another device embodying the features of the present invention and in which the displace ment of the conducting gas is performed by an explosive action;

Fig. 4 is a cross section on the line 4-4 of Fig. 3 looking in the direction of the arrows;

Fig. 5 is a cross section on the line 55 of Fig. 3 looking in the direction of the arrows;

Fig. 6 is a cross section on the line 6-6 of Fig. 3 looking'in the direction of the arrows;

Fig. 7 is a longitudinal section through another embodiment of the features of the invention in which the displacement of the conducting gas is accomplished by a bodily expulsion action as for example by the use of a piston;

Fig. 8 shows across section on the line 88 of Fig. 7 looking in the direction of the arrows; v r

Fig. 9 shows a cross section on the line 99 of Fig. 7 looking in the direction of the arrows; and 5 Fig. 10 shows a cross section on the line 10-10 of Fig.7 looking in the direction of v the arrows.

Figures 5, .6, 9 and 10 are on enlarged scale as compared to Figures 3 and 7.

Referring first to the construction shown in Figs. 1 and 2, in this case there is a cylindrical chamber 12 of nonconducting and highly insulating material, and a material which is also perfectly gas tight and not affected by the gas contained therein. For example, the tube 12 may be of glass or special composition such as fibre or the like. In its upper end the tube 12 carries an electrode 13 which is one of the electric terminals in contact with the gas containedin the tube. This electrode 13 is preferably in the form of a disk on the lower end of a pin 14 which reaches downwards from a cross bar 15 extending across a circular gasket 16 resting against the upper end of the tube 12. A,

ferrule 17' is secured to the upper end of the tube 12 in any permanent and gas tight manner, as by means of a lining 18 of lead or the. like poured into place. The ferrule 17 is externally threaded to receive a cap 19; and in order to insure a perfectly gas tight seal at the upper end of the tube a washer or gasket 20 may be set into place against the ring or gasket 16 before the cap 19 is drawn home.

Near the lower end of the tube 12 is located another electrode 21. This electrode is suitably supported in a manner to be presently explained; and the current flows between the electrodes 13 and 21 by reason of the conducting quality of the gas contained within the tube 12.

A. ferrule 22 is mounted'on the lower end of the tube 12 and is sealed thereto in gas tight fashion as by means of the lead seal 23. This ferrule is externally threaded so that it can be threaded into a thimble 24; and the lower end 25 of said thimble is externally threaded so that it can be threaded into the roof 26 of a chamber 27. If desired a gasket may be placed between the thimble and the roof 26 so as to insure a gas tight seal when the thimble is threaded down tight.

The external diameters of the cap 19 and the thimble 24 are substantially equal, and both of said parts are conveniently made of a form to be set easily between suitable clips. In this case the entire 'unit can be conveniently manipulated as a unit in the nature of a fuse, and it can be readily snapped into place between the clips or withdrawn from them without difiiculty. I do not herein deem it necessary to illustrate or describe said clips indetail as structures of this kind are wellknown and understood in the art.

The chamber 27 with its roof 26 is gas tight and therefore when the lower end of the tube 12 is placed in communication with said chamber the gas pressures in the two parts are equalized and will be maintained in the equalizedpressure. When the device is in service to conduct the current of the circuit the gas within the tube 12 is of the proper characteristics, bothas to composition and pressure, to conduct the current between the electrodes 13 and 21. When, however, the current becomes abnormally large the condition of said gas is modified either as to pressure or composition or both in such a manner as to change the conductivity between the electrodes13 and 21 so as to establish practically a perfect insulation between these parts.

In the construction illustrated in Figs. 1 and 2 I have provided means for normally isolating the tubular chamber 12 from the chamber 27 as long as the normal condition is maintained in the circuit, but thereafter establishing communication between said chambers when an abnormally large current flows in the circuit. Insome cases the pressure of the gas in the tubular chamber 12 is initially lower than that in the chamber 27 so that when the communication is established between said chambers a new and balancing pressure is established which is of anamount that destroys the conductivity between the electrodes. chamber 12 normally contains a gas of such composition that it is a conductor, whereas the chamber 27 contains gas of some other composition; so that whenthe gases of both of said chambers are allowed to intermingle or come to a balanced condition the conductivity between the electrodes is destroyed.

In the particular construction illustrated I place a thin diaphragm 29 at the lower end of the tubular chamber 12 and over the opening 30 which leads into the large chamber 27. Said diaphragm may be of relatively thin metal such as fairly heavy tin foil, or it may 1 be of suitably oiled or chemically treated paper or any other suitable material. The diaphragm is sufliciently strong to resist the difference in pressure between the two chambers in air tight fashion, but nevertheless of such a nature that it can be easily ruptured. As a matter of convenience also a gasket 31 may be placed between the edge of the diaphragm and the lower end of the cartridge tubular member as illustrated in Fig. 1. This gasket 31 is conveniently made of conducting material such as copper so as to establish an electric connection with the ferrule 22. A sleeve 32 is placed within the lower end of the tubular member 12 and in connection with the gasket 31. A bridge piece 33 reaches across the upper end of the sleeve 32 and serves as a guide for the lower end of a plunger pin 34. Said plunger pin is slidably mounted in the center of theelectrode 21, and a spring 35 normally tends to force the pin downwards. The. plunger pin below the position of the spring i formedof conducting material where it passes through the bridge piece 33, and is of insulating material above said point.

A fuse element 36 extends between the electrode 21 anda collar 37 on the pin 34 and said fuse element normally retains. the pin 34 in raised position as indicated in Fig- 7 1. Furthermore, the electrode 21 is insulated from the bridge piece 33 by means of an insulating collar 38. Consequently, the electric current must flow from the electrode,- through the fuse'36, through the lower portion of the plunger pin,'into the bridgepiece 3i}, and thus through the sleeve 32 and to the ferrule 22. By reason of this arrangement it follows that practically the full current will pass through the fuse 36 in flowing to or from the electrode 21. If desired, a very flexible pigtail 39 will be extended between the collar 37 and the bridge piece 33 so that the current will be carried thereby instead.

of throughthe sliding contact between the pin and the bridge piece.

If desired, a suitable check valve 40 may be provided in the chamber 27, preferably inthe roof 26 thereof, so as to allow the gas in said chamber to be readily re-adjusted. either as to pressure or composition or both after the circuit has been opened. a

Theoperation of this device is as follows: Assuming, for example that the tubular chamber 12 is filled with-neon gas of a pressure of substantially 6-10 mm. mercury, absolute pressure, the same will constitute a good conductor for high voltage currents and of relatively low resistance, between the electrodes 13 and 21. These electrodes will be separated whatever distance is required according to the voltage which the device is intendedto open; but ordinarily such separation should probably be 1 inch per 10,000 volts for which the device is designed. In some cases it may be desirable to use a greater amount of separation than the above.

Assuming alsothat the chamber 27 is filled with air at atmospheric pressure, upon rupturing the diaphragm 29, this air will rush into the chamber 12 and immediately raise the gas pressure thereof to full atmospheric pressure, besides which the neon gas will be tremendously diluted by the influx of air. As a consequence the conductivity between the two electrodes will be destroyed and the high voltage current will be effectively blocked. In connection with the foregoing it will be understood that the electrode 21 is suitably perforated so as to allow the gas or air from the chamber 27 to enter into the body of the chamber 12 and intermingle with the gas therein.

Instead of having the chamber 27 filled with air at atmospheric pressure it might be filled with any other'suitable gas at either atmospheric or other suitable pressure so that the proper action of the destroying of the conductivity in the chamber 12 will be per-.

formed. Or the chamber 27 might be practically perfectly evacuated so that upon rupturing the diaphragm the gas pressure inthe pend on the relative sizes of the chambers 12 and 27 as well as the relative absolute pressure therein. p

In some cases the chamber 27 'may be entirely dispensed with and upon rupturing the diaphragm 29 ordinary atmospheric air will be allowed to rush into the chamber 12 and intermingle with the rarefied neon gas so as to destroy its conductivity.

In other cases other gases than neon may be used since manifestly any suitable composition and pressure of gas may be used which will. have suitable conductivity, which conductivity will be destroyed by the change of pressure of the composition.

Referring next to the structure shown in Figs. 3, 4, 5 and '6, in this case the upper tubular chamber 41, of glass or other suitable material, is provided with the electrode 42 at its upper end, together with a ring 43 to which said electrode is connected by the stem 44. A ferrule 45 is sealed to the upper end of the tube 41 by the lead or other seal 46.

placed in the lower end'of the tube 41.

5 so that the oiled or prepared paper is placed across the upper end ofthe tube 41, and a gasket seal is provided for sealing the edge of said diaphragm in a gastight manner. This diaphragm is of such physical strength to resist the difference of pressures existing on its twofaces, being the diflerence of pressure within the tube 41 as compared to atmospheric' pressure. Another electrode 51 is This electrode 51 is supported from the. cap 52 by means of the studs 53 and 54 of insulating material. The cap 52has the threaded flange 55 which threads on to the ferrule 56,

said ferrule being sealed to the lower end of the tube 41 by the lead or other seal 57. Preferably a gasket 58 is placed between the cap 52 and the end of the tube 41 and the ferrule 56 so as to establish a gas tight seal. w

A fuse link reaches from the cap 52-t0 the electrode 51; and said fuse link is adapted to blopv with the excessive current of an overload. The diaphragm 51 is perforated with numerous perforations as shown in Fig.

as pressure momentarily generated by the lowing of the fuse 59' will be communicated into the space within the tube 41; and by proper arrangement andproportion of the parts the amount of pressure thus communicated through the perforations 60 will be suiiicient to increase the pressure within the tube 41 to such a point as to rupture the diaphragm 49. Immediately theconditions of pressure and composition of gas with- .in the tube 41 will be so modified as to destroy the conductivity of the gas within the tube and thus definitely open the high tension circuit. .Tlie structure shown in Figs. 7, '8, 9 and 10 is similar to that of Figs. 3,4,

I 5 and6 in many respects; and the upper end of the tubular chamber 41, as well as the arrangement of the electrode 42, diaphragm 49, etc., is similar to or the same as that already explained.

ton. Thiswill cause a sufficient compression of gas in the upper portion of the tubular chamber to rupture the diaphragm 49'; or in some cases the electrode can be provided with points or projections adapted to bodily strike against diaphragm 49 and rupture the same when the piston reaches the upper end of the tubular chamber. For example, in the construction illustratedthe electrode 61 is provided with an upstanding flange 63 having a relatively sharp upper edge, said This elec flange being adapted to travel past the fixed electrode 42 and physically cut out the diaphragm 49.

It will be noted that in each of the three forms of construction particularly described herein the fuse element which primarily opens with overload canbe very easily replaced, and

conductivity of the current through the gas;

the composition or pressure or both of the gas being subject to modification upon the existence of an overload condition in such a way as to destroy the conductivity of the gas body fofhigh voltage currents.

Furthermore, it will be understood that the cross sectional area of the gas conductor will usually be substantially in proportion to the total -volume of current thereby conducted, and the conductivity per square inch of cross sectional area will depend upon the composition or pressure of the conducting gas. It will also be understood that the normal distance between the electrodes should be selected according to the operating conditions, and particularly according to the voltage which is to be opened. Ordinarily, the normal separation between the electrodes will be substantially in proportion to the line voltage, and this separation should be such that no arcing willoccur or be maintained between the electrodes and under the full main line voltage, afterthe pressure and composition of the gas have been modified for the purpose of destroying the conductivity of the system.

Furthermore, it will be'understood that in mentioning a particular pressure of neon gas as being available for the normal conducting condition, still by mentioning the same I do not intend to limit myself thereto except as I I may do so in the claims.

Examination of the construction of Figs. 1 and 2 shows that the diaphragm 29 of said. construction is placed in very close proximity to the fuse 36 thereof. Consequently, when said diaphragm is ruptured the metallic gases generated by the blowing of the fuse are very close to the opening created by the rupturing of the diaphragm, so that said metallic gases are very easily dissipated into the atmosphere; As a result of this circumstance the tendency of said gases tomaintain the arc is greatly reduced.

Furthermore, in the particular construction illustrated in Figs. 1 and 2 the fuse and diaphragm are placed close'together and at the lower end of the tubular chamber. Said arrangement might be inverted, placing the ing in the form of circular plates.

fuse and the diaphragm at the upper end of the structure.

In the different constructions illustrated in the drawings, the electrodes are shown as be- In place thereof any other suitable form and composition of electrodes might be substituted. For example,'said electrodes might be of carbon in the form of cylinders; and in fact such form and compositions of electrodes is especially desirable to use in the case of neon gas.

Experience has demonstrated that there is a substantial drop of voltage at the surface of contact between the electrode and the gas body, this drop of voltage representing a loss of energy in the form of heat. In the case of neon gas it is desirable to use carbon electrodes in order to reduce this drop, and experience will demonstrate that in the case of any particular gas and pressure thereof it will be most desirable to use a particular composition and arrangement of electrodes.

It will be understood that the conductivity destruction is accomplished either by change of the composition of the gas or its pressure or both. By the'term composition as thus used in the specification and claims I mean change of chemical or physical composition since manifestly the admixture of air and neon gas as a physical admixture and does not modify thechem1cal composition of the neon. In some cases the change of composition may be chemical and brought about either by ad mixture or other gases or in any other manner.

It will be noted. that in each of the constructions herein illustrated and described, the gas occupies the space around the fusible element,

so that the conductivity of'such gas around the fusible element supplements the conductivity of the fusible element itself. Therefore a small portion of the current flowin through the device will pass through suc gas in shunt with the current flowing through the fusible element, with corresponding reduction of current through the fusible element. However, the conductivity of the fusible element is much greater than that of the gas so shunting, and the great bulk of the current will flow through the fusible element itself, and be effective to heat and fuse said fusible element for the intended purpose. Furthermore, whatever may be the ratio between the conductivity of the gasin shunt with the fusible element as compared with the conductivityof the fusible element itself, such ratio will remain practically constant in any given device, so that there will be assurance that under the predetermined overload conditions an excessive amount of current will flow through the fusible element and cause it to blow. ,When that takes place the conditions of the gas itself will be so altered that it will become practically a nonconductor and will open the circuit as already explained hereinbefore.

I do not intend to limit myself thereto except as I may do so in the claims. I

1. A device for the purpose specified comprising in combination a sealed chamber for conducting gas, a fixed electrode at one position in said chamber, a movable electrode at another position in said chamber, an electrical connection from the exterior of the chamher to the first mentioned electrode, an electrical connection 'fromthe exterior of. the chamber to the second mentioned electrode, a fusible element in the second mentioned connection and within the chamber, adapted to fuse under excessive current, and means in conjunction with the second mentioned electrode to modify the condition of the gas in the chamber when said fuse blows, to thereby destroy the conducting quality of'said gas, substantially as described.

2. A device for the purpose specified com prising a sealed chamber, a relatively thin but gas tight diaphragm constituting a portion of the enclosure thereof, a fixed electrode within said chamber, another electrode within the chamber, a connection from the exterior of the chamber to the first mentioned electrode, a connection from the exterior of the chamber to the second mentioned electrode and including a fusible element within the chamber, and suitable conducting gas normally sealed within the chamber and adapted to be modified into nonconducting condition when the fuse blows due to overload, substantially as described.

3. In a device for the purpose specified the combination of a sealed chamber, a pair of separated electrodes therein, suitable connections from the exterior of the chamber to both of said electrodes, suitable conducting gas within the chamber and between the electrodes, a fuse element in the circuit with one electrode, and means for destroying the conducting quality of said gas when said fuse blows under overload condition substantially as described.

4. A device for the purpose specified including in combination a sealed chamber, a pair of separated electrodes within said chamber, connections'between the exterior of the chamber and both of said electrodes, neon gas having a pressure of substantially 6-10 mm.

cury absolute pressure within said chamber and between the electrodes, a relatively thin but gas tight diaphragm constituting a portion of said chamber, and means for rupturing said diaphragm when an excessive current flows in the circuit including said electrodes, to thereby modify the conditions of pressure and composition of said gas and destroy the J conductivity thereof substantially" as described. I V

6. In a device for the purpose specified the combination of a closed chamber, a pair of separated electrodes therein, suitable conducting gas in said chamber and between said electrodes,and means for modifying the condition of said gas upon the existence of overload in thecircuit which includes said electrodes, to thereby destroy the conducting quality of said gas, substantially as described.

7. The method of opening a high tension electric circuit under overload conditions whichconsists in normally passing the current through a body of gas having a composi tion and pressure such as to afiord a path of relatively high conductivity, and which consists in modifying the condition of said gas upon the existence of an overload condition ,in the circuit, to thereby destroy the conductivity of said gas and openihg the circuit, substantially as described. 8. The method of opening a high tension circuit under overload conditions, which consists in normally'passing the current through a body of gas having a relatively high con ductivity, and which further consistsin modifying the pressure of said gas upon the existence of an overload condition to therebydestroy its conductivity and open the circuit, substantially as described.

9. In a device for the purpose specified the combination'of a closed chamber, a pair of separated electrodes of carbon therein, neon gas substantially occupying the space within said chamber and between the electrodes and to the substantial exclusion of other gas, and means for modifying the condition of said gas upon the existence of overload in the circuit which includes said'elctrq'des, to there by destroy the conducting quality of said neon gas substantially as described.

' ALLEN S, PEARL. 

